1. Field of the Invention
The present invention relates to an armature winding apparatus for winding a coil around an armature of a motor, and particularly to an improvement of a cutting device for severing coil leads at start and finish of winding of each coil, which are connected to hooks of an armature commutator, at a position close to connection portions thereof.
2. Description of the Related Art
Conventionally, there is a dual drive winding apparatus, as an armature winding apparatus for winding a wire (enamel copper wire) fed from a rotating flyer around an iron core of an armature.
This winding apparatus includes a collet unit for gripping an armature shaft at an armature commutator side of the armature, which is fixedly provided with an armature core and the armature commutator (hereinafter abbreviated as xe2x80x9cthe commutatorxe2x80x9d) on the same axis with a predetermined space being provided therebetween, and for performing indexing rotation while maintaining the axis line horizontal. Support shafts perpendicularly intersecting the axis line and moving close to or away from each other are provided at both sides in a horizontal direction with the armature axis line therebetween, wire-winding chucks for holding the armature core therebetween are swingably mounted at tip end portions of the support shafts, and a pair of flyers for feeding a wire for coil winding are rotatably mounted.
At the time of winding, prior to the rotation of the flyers, the above-described support shafts are moved in a direction to be close to each other to hold the armature core from both sides by a pair of the wire-winding chucks and simultaneously cover slots other than the wire-winding portions to lead the wires fed from the flyers to required two slots.
Further, after leads of the wires are gripped by grippers and by utilizing reverse rotation of the flyers, the coil leads of the start wires fed from the flyers are looped around hooks of the commutator to be connected thereto, the collet unit is made to perform indexing rotation to bring the armature in a predetermined rotational position, and the wires are wound around the required two slots of the armature core by rotating the flyers to thereby form first coils. At this point of time, the coil leads at the start of winding gripped by the grippers are severed by cutters, and a pair of the wire-winding chucks are retreated from the armature core.
Next, the collet unit is made to perform indexing rotation to place second hooks at the same positions as those of first wire connection positions, and the leads of the first coils at the finish of winding are made to be leads at the start of winding of second coils. In this manner, the same operations are repeated one by one to perform winding of the coil and connecting of the coil leads to the hooks, and the coil leads at the finish of winding are finally gripped by the grippers and severed by the cutter to finish winding wire for the armature.
There are some armatures in which the leads are pulled off by rotation of the armature instead of the leads at the start and the finish of winding of each coil being severed by the cutter.
However, in the conventional armature winding apparatuses as described above, depending on the cutting devices, in some armature winding apparatuses in which the leads at the start and the finish of winding of each coil are severed by cutters, the cutters have to pass through spaces between the grippers, flyers, the collet unit and the like to retreat so as not to interfere with them. For this reason, it is difficult to optimally select the positions of the cutters, and thus it is extremely difficult to sever the wound coil leads at the position close to the hooks to which they are connected.
When wires are to be wound around various kinds of armatures by the same armature winding apparatus, the position of the cutters has to be finely adjusted each time when a diameter of the commutator of an armature differs, thus causing the disadvantage that tremendous time and efforts are required to adjust it.
The armature winding apparatuses in which leads of the coils are pulled off by rotating the armatures have the disadvantage that they are applicable to only an extremely narrow range, because the hooks to which the coil leads are connected are sometimes bent when the wires with large diameters are wound around them, and severing of the wires are sometimes difficult depending on the shapes of the commutators.
Further, in order to eliminate the disadvantages as above, as shown in FIG. 19, a cutting device, which is constituted by attaching a single blade cutter 20 to a tip end portion of an outer shield 16 forming an external cylinder of a collet unit 10 gripping an armature shaft 2 of an armature 1 so as to cut the leads of the coils by movement of the outer shield 16 in the axial direction, is proposed.
However, with the cutting device as described above, it is necessary to provide the cutter 20 at an outer circumferential side of the hook 6 since the commutator 4 has to be inserted into an inside of the outer shield 16, and thus the coil leads cannot be severed to be the shortest.
As described above, in each of the armatures with wires being wound around by the armature winding apparatuses provided with the conventional cutting devices, the lead of each coil considerably protrudes from the hook of the commutator, to which the coil lead is connected, and therefore there is the fear that the protruding portion of the lead touches an adjacent commutator bar to short out, or catches on other components and falls off the hook when the lead of the coil is welded to the hook.
This invention is made to eliminate the above-described disadvantages, and its object is to make it possible to sever leads at start and finish of winding of a coil wound around an armature core at a position close to a connection portion of a wire looped around a hook of a commutator by means of an armature winding apparatus.
This invention is applied to an armature winding apparatus including a collet unit having on an outer circumferential portion an outer shield movable for a predetermined distance in a direction of an axis and an inner shield (also called a thimble) rotatable at a predetermined angle around the axis, flyers for feeding and winding wires to slots of an armature core supported to be able to perform indexing rotation by the collet unit while rotating to form coils in succession, a mechanism for looping wires at both end portions of the coils around hooks of an armature commutator, and cutting devices for severing leads of the coils at start and finish of winding.
In order to attain the above-described object, the above-described cutting devices are constituted by cutter mounting members attached to the above-described outer shield to be displaceable within a plane including the above-described axis and move with the outer shield in the direction of the above-described axis, and the cutters provided at tip end portions of the cutter mounting members to be able to advance and retreat to and from the above-described axis.
The cutter mounting member of the cutter device can be inserted to be displaceable between a pair of side walls extensively provided at the above-described outer shield to be displaceable. Further, the cutter mounting member is attached to the above-described outer shield to be swingably rotatable within a plane including the above-described axis, or attached to be able to advance and retreat in parallel with respect to the above-described axis.
Further, it is suitable that the cutter mounting member has cutter ingress means for making the above-described cutter get into the armature core side at a hook root portion of the armature commutator by rotating the above-described inner shield a predetermined angle around the above-described axis.
The cutter ingress means can be constituted by adjustment screws screwed into the above-described cutter mounting member to be able to advance and retreat in a direction to intersect the above-described axis perpendicularly, cam surfaces, which are provided at an outer circumferential portion of the above-described inner shield and are able to be engaged with the above-described adjustment screws, and biasing means for pressing the above-described adjustment screws against the cam surfaces.
Further, the cutter of the above-described cutting device may be constituted by a movable blade integrated with the above-described cutter mounting member, and a backing blade, which is provided to oppose the movable blade, biased in a direction to be pressed in contact with the above-described cutter mounting member, follows movement of the above-described cutter mounting member following retreat of the above-described outer shield, and moves with the above-described cutter mounting member until it abuts against the above-described inner shield and stops.
Furthermore, it is further preferable to provide a wire presser capable of pressing a wire connection portion of the hook of the armature commutator at an inner circumferential portion of the above-described inner shield to be movable in the direction of the above-described axis.
As a result that the cutting device is constituted as described above, the armature winding apparatus according to this invention can use the movement of the outer shield and the inner shield for the cutting device, which is conventionally used for the collet units of the armature winding apparatuses, facilitates winding of the wire fed from the flyer around the armature core by covering the hook of the commutator when a coil is wound, and facilitates wire connection by exposing a required hook when the coil lead is connected to the hook. Thus, the cutter member normally retreats outside to facilitate attachment and detachment of the armature to and from the collet unit, and it can get into an inside at the time of severing the lead of the coil and sever the coil lead at the position close to the wire connection portion of the hook.
The above and other objects, features and advantages of the invention will be apparent from the following detailed description which is to be read in conjunction with the accompanying drawings.